1. The lowering of level of LDL by therapy
of statin and ezetimibe, used as a
prevention of atherosclerosis.
Abstract
Atherosclerosis is a chronic disease of thearterial walls, which leads to complication such as
myocardial inflammation and strake. By understanding the results and conclusion from experimental
clinical trials, it may be possible to preventatherosclerosis. Most important is to understand the
biological principles behind atherosclerosisgenesis because it provides us with information of
possible ways to overcome obstacles and bring the solution of lowering LDL-lower density
lipoprotein which is cholesterol, which is responsible for atherosclerosis.
Introduction
General conception of atherosclerosis genesis.
Libby P. et.al, in the Nature article, described atherosclerosis as the development of plaque in the
inner membrane of arteries (fig. 1).
The normal muscular artery and the cell changes that occur during
disease progression to thrombosis are shown. a, The normal artery contains three layers. The inner layer, the tunica intima, is
lined by a monolayer of endothelial cells that is in contact with blood overlying a basement membrane. b, The initial steps
of atherosclerosis include adhesion of blood leukocytes to the activated endothelial monolayer. c, Lesion progression
involves the migration of SMCs from the media to the intima, the proliferation of resident intimal SMCs and media-derived
SMCs, and the heightened synthesis of extracellular matrix macromolecules such as collagen, elastin and proteoglycans. d,
Thrombosis, the ultimate complication of atherosclerosis, often complicates a physical disruption of the atherosclerotic
plaque.
Furthermore, they proved that by examinationof humans and animalswas a show changes in the
monolayer of endothelial cells, which poses attachment to white blood cells. This evidence
suggested that changes such as this allow LDL entry by permeable endothelial cells to the artery
wall. Cholesterol is there chemically modification by intima express scavenger receptors in the
oxidation process.Davis Jr. H.R. et.al, in Atherosclerosis articles from 2011 had been suggested that
primary events of atherosclerosis were inhibiting Apo-apolilipoprotein modification which was
triggered of modification, inflammatory immune system and accumulation of lipoprotein like LDL.In
addition, Libby P. et.al, believed that cholesterol undergoes endocytosis process by monocyte- white
blood cell occurred in plague, what leads to cholesterol accumulation and migration to feather level

2. of artery, called tunica intima, where changed into macrophages and when engulfsmore lipoprotein
in foam cell. They explained that atheroma, region where atherosclerosis begins formation,
produced the migration of muscles from media to intima. In fact, this made extracellular matrix
molecules: including collagen and elastin, which together with platelet, mediated by smooth muscles
form fibrous cap. Libby P. et.al, point out, thatin this cap foam cells realised: lipids and macrophages
bodies, which eventually die and accumulated in there in the process of not efficient clearance
called efferocytosis. Above all,accumulation of cellular derbies and extracellular lipids are formed
rich of fat pool called by the authors’ necrotic core of plague. In result,that plaque becomes bigger
and bigger, which eventual produced thrombi, caused limiting flow of blood. (Libby P. et.al; 2011)
Methods
Mouse model, as an understanding of potential drug therapy .
In order to prove theory of Altmannet.al published in Science article from 2004, which identified
cholesterol transporter called Niemann- Pick like protein in short NPC1L1, placedon the membrane
of intestine, as a target of new agent called ezetimibe (fig. 3), which can inhibit that transporter,
Davis Jr. H.R. et.al, in Atherosclerosis articles from 2011 had been usedmice models as a tool to
understand a complex of pathways involved in atherosclerosis disease, which developed evaluation
of potential ezetimibe therapy. In first experiment, they was used the two mouse one with npcl null
andsecond-wild type mice. In comparison with wild type mice,mice with null npc1l1 show 86%
reduction in cholesterol absorption and 72% of inhibition of intestinal cholesterol uptake. In
additional results was proved that a wild type mouse was insensitive to treatment with ezetimibe. In
this wayDavis Jr. H.R. et.al had been defined direct interaction between ezetimibe and NPC1L1 and
identification of mechanism of high affinity binding ezetimibe to NPC1L1, which is 61- amino acid
site of extracellular loop C in NPC1L1. These findings lead to the conclusion that ezetimibe prevents
NPC1L1 from cholesterol uptake.
fig. 3. Mechanism of action
for reduction of atherogenicApoB-containing lipoproteins by ezetimibe, and potential effects on atherosclerotic
burden.ApoB = apolipoprotein B, CE = cholesteryl ester, CETP = cholesteryl ester transfer protein, FFA = free fatty acid,
HDL = high density lipoprotein, IDL = intermediate density lipoprotein, LCAT = lecithin-cholesterol acyltransferase,
LDL = low density lipoprotein, LPL = lipoprotein lipase, NPC1L1 = Niemann-Pick C1 Like 1 sterol transporter, SR-
B1 = scavenger receptor type B1, TG = triglyceride, VLDL = very low density lipoprotein.

3. Second experiment was based on the work of Mahley R.W. et.al, publishes in Annual Review
Genomics Human Genetics, from 2000 and Plump A.S. et.al, published in Cell from 1992, which
suggested that ApoE- lipoprotein E genotype was essential for normal catabolism of trigriceride–rich
protein consistent (fig. 2). In that publication ApoE was mapped in 19 chromosome and protein
produced from that is targeting X receptor liver, which play important role inregulation of
metabolism of cholesterol.Davis Jr. H.R. et.al, show that Apo E knockout mouse was developed the
hypercholestelemia and premature atherosclerosis similar in characteristic to human; indeed they
treated those mice with ezetimibe.Apo E knockout mice was received; a high-fat western diet (40
kal% butter fat, 0.15% cholesterol), or low-fat diet (10 kal% butter fat, 0.15% cholesterol), or semi-
synthetic, cholesterol free diet (10 kal% corn oil) with or without ezetimibe treatment.
Results
As a consequence of that treatment was reduced the plague for about 57%, coronary arterial
occlusion 68%, myocardial fibrosis 57% and cardiomegaly 12 % with compered in untreated control
mice. Davis Jr. H.R. et.al, in brief proved that ezetimibe was inhibit absorption by 90 % and
significantly lower plasma cholesterol. Conclude from this experiment ezetimibe was produced
reduction in atherosclerotic lesion surface area of the entire aorta from 20% to 4% in mice feed the
western diet and from 24% to 7% in the low-fat cholesterol diet. (Davis Jr. H.R. et.al; 2011)
fig.2. Representative
−/−
aortic arch images from male apoE mice following 6 months of diet ± ezetimibe Davis et al.

4. Result of clinical test of ezetimibe and statin
Introduction
High level of LDL is correlated with high risk of cardiovascular complication such as
atherosclerosis.Clinical trials from 2009 and 2010 prove that new agent called ezetimibe can inhibit
that transporter and reduce level of LDL of about 20% in individuals being treats with statin for long
period. Statin are popular inhabitants of hydroxymethyl grutaryl co-enzyme a reductase in short
HMG CoA reductase inhibitor which regulate pathway of LDL production in liver. Research found
that statin is most effective in therapy with cardiovascular disease as well as prevention of that
disease for people with CVD family history. Statins are have side effects of muscular damage and
research also found that statin lowering LDL level but risk of cardiovascular disease still high.
Ezetimibe commercial name is Zetia or Ezetrol together with statin called Vytorin and Inegu.
Methods
Research from 2009 and 2010 shows that ezetimibe did not improve outcomes significantly,
however in 2010 clinical trials was show that together with statin results significantly improved.
Studies of trials ENHANCE and ARBITER-6 was suggested that ezetimibe effectively lowering LDL
plasma, but doesn’t effect on atherosclerosis (tab. 1 and tab. 2). Recent studies from April 2011 in
Arteriosclerosis was proved that adding ezetimibe to statin could regress atherosclerotic plague that
was measured by MRI. A study was involved 67 PAD-with peripheral arterial disease patients. There
were 16 patients whose was treated by simvastatin 40 mg, 18 patients whose was treated by
simvastatin 40 mg and 10 mg ezetimibe and 33 patients whose was chosen with LDL-C level above
80 mg/dL and was treated with open –labelled ezetimibe 10 mg on top of statin therapy before. In
the therapy patient was treated regularly and the plunge picture was taken in first and second year
after therapy.(West et.al, 2011)
Results
Results was showed that with the statin treatment baseline was at beginning 118 mg/dL and was
reduced to 91 mg/dL in first year and 83 mg/dL in second year volume of plague. Results was
showed that with the statin+ezetimibe treatment baseline was at beginning 118 mg/dL and was
reduced to 67 mg/dL in first year and then start increase to 68 mg/dL in second year volume of
plague. Results was showed that with the ezetimibe treatment baseline was at beginning 100 mg/dL
and was reduced to 80 mg/dL in first year and 71 mg/dL in second year of volume of plague. (West
et.al, 2011)

5. LDL levels (tab1)
LDL cholesterol (mg/dL) Simvastatin Simvastatin/ezetimibe Ezetimibe (on top of current statin)
Baseline 118 118 100
Year 1 91 67 80
Year 2 83 68 77
Plaque volume (tab2)
Plaque volume (cm3) Simvastatin Simvastatin/ezetimibe Ezetimibe (on top of current statin)
Baseline 11.0 11.5 10.0
Year 1 10.3 11.1 10.4
Year 2 10.5 10.5 10.8
Conclusion
Definitively benefit of statin and ezetimibe in seen when studied this trials. Conclusion of ezetimibe
working alone doesn’t exist yet, but with proving of reduction low –density lipoprotein make good
contribution to conclusion that may take place in 2013 on trial called- IMPROVEIT- IMProved
Reduction of Outcomes: Vytorin Efficacy International Trial.
Reference
1. Atherosclerosis215 (2011) 266-278 “Effects of ezetimibe on atherosclerosis in preclinical models”
Harry R., Davis Jr., Robert S. Lowe, David R. Neff; Available online 17 February 2011
2. Nature473, 317-325 19 May 2011 “Progress and challenges in translating the biology of
atherosclerosis” Peter Libby, Poul M. Ridker, Goran K. Hansson; Published online 18 of May 2011.
3.Atheriosclerosis 218(1), 156-62 2011 Sep; Online publication Jan 2012“The effect of ezetimibe on
peripheral arterial atherosclerosis depends upon statin use at baseline” West AM., Anderson JD.,
Meyer CH., Epstein FH., Wang H., Hagspiel KD., Berr SS., Harthun NL., DiMaria JM., Hunter JR.,
Christopher JW., Chew JD., Winberry GB., Kramer CM.